Cruise ship Thomson Celebration will change the itinerary of its Red Sea Magic cruise following further unrest in Egypt and the kidnap of two American tourists.

Growing anger over the deaths of 74 fans at a football match in Port Said this week has led to more demonstrations in Cairo. On Friday a government building was set on fire and a demonstrator and a soldier were killed as police fired tear-gas at stone-throwing rioters. More than 1,000 were injured.

In an unrelated incident, two women in their 60s and their Egyptian guide were seized by Bedouin gunman as they returned from St Catherine's Monastery to their hotel in Sharm el Sheik. They were later released unharmed. Earlier in the week, Bedouins kidnapped 25 Chinese workers in the north of Sinai in protest at the imprisonment of fellow tribesmen for drug-trafficking and robbery.

The Americans were travelling through Wadi al-Sual, about 25 miles from St Catherine's, when a masked men armed with machine guns forced their mini-bus to stop. The gunmen took the tourists' money before forcing the two women and their guide into a vehicle which drove into the mountains. They were freed several hours later.

Egyptian Tourism Minister Munir Fakhri Abdul Nour said the Americans had assured him that they were in good health and had not been mistreated.

The normal itinerary for Celebration's seven-night Red Sea Magic cruise would have seen it docking in Port Sokhna on Monday for its 1,250 passengers to take a 90-minute bus ride on excursions to Cairo and the Pyramids. Instead, the ship will spend the day at the Israeli port of Eilat.

A Thomson statement said: "We are aware of the kidnapping of two US tourists on an excursion to St Catherine's Monastery. We are monitoring the situation closely and as a precautionary measure have cancelled all excursions to Cairo and St Catherine's up until and including Monday. Our cruise ship Thomson Celebration will also not stop at the Port Sokhna on Monday and instead will make an additional call at Eilat in Israel.

"The safety of our customers is always our number one priority and we will continue to assess the situation and work with the Foreign and Commonwealth Office. We will update customers accordingly, should any further decisions be made regarding our excursions and ports of call of our cruise ship.

"The vast majority of our tour operations are in Sharm el Sheikh. People can take considerable reassurance from the fact that the resort operates like a country in itself, run separately from the rest of Egypt."